Recent research shows that when the size of the gold nanoparticles is reduced to that of the gold nanoclusters, they have specific fluorescent properties other than surface plasmon resonance. Because the gold nanoclusters have advantages such as a lower toxicity than the semiconductor fluorescence quantum dots and high light stability, the gold nanoclusters have great potential in the applications of biosensing and bioluminescence labeling. However, conventional methods for synthesizing the gold nanoclusters and modifying their surface are complicated and time-consuming. If bio-molecules should be conjugated on the gold nanoclusters, the more complicated and time-consuming processes cannot be omitted.
Accordingly, a process for easy preparation and surface modification of the gold nanoclusters is desired in the industry. Furthermore, the gold nanoclusters may utilize for detecting thiol-containing compounds.